[0001] The present invention relates generally to the loading of articles into containers,
and more particularly to a process and apparatus for loading articles into flexible
plastic containers. Meat articles have conventionally been manually loaded into flexible
plastic packages for either shipment or display. While many aspects of meat packaging
process had been refined to a high degree of automation, the actual step of placing
meat articles into containers has remained a substantially manual operation wherein
an operator receives the cut of meat from a conveyor, selects an appropriately sized
container and slides the meat from a shelf into the container. The subsequent processing
steps of vacuumizing, clipping and shrinking are highly automated but remain dependent
upon being supplied from a manual container loading step.
[0002] An attempt to overcome the shortcomings of prior art manual handling of meat cuts
is described in United States Patent No. 3,942,624. The apparatus described therein
is a bag loading apparatus which comprises a cantilevered conveyor system such that
a meat article may be placed on one end of the conveyor while a bag is draped around
the cantilevered end of the conveyor. The movement of the conveyor causes the meat
article to move along the conveyor. While this apparatus overcomes many of the shortcomings
of the prior art, it utilises a plurality of conveyor belts which, of necessity, are
grooved or otherwise roughened so as to prevent any sliding during the conveying process.
[0003] In the meat handling art it is necessary to maintain a high degree of sanitary cleanliness
of all meat-contacting surfaces, and the use of grooved conveyor belts is not conducive
to such sanitary conditions. Another shortcoming of the cantilevered belt conveyor
device resides in problems associated with tracking and maintaining parallelism of
the long narrow cantilevered belt conveyors. An additional problem with this prior
art device is associated with breakdown in a meat packaging line. Inevitably breakdowns
and power failures occur and, due to the nature of the belts, meat articles must be
carried past the conveyor to the packaging station, this effectively causing a breakdown
and bottleneck in the entire meat packaging line.
[0004] It is an object of this invention to provide a method and apparatus for loading articles
into containers, wherein the contacting surfaces are readily cleanable.
[0005] According to one aspect of the present invention we provide apparatus for conveying
articles in a direction of progression, characterised by two sets of beams, at least
one of said sets being horizontally movable relative to the other set and at least
one of said sets being vertically movable so as to be positioned alternately above
and below the remaining set; and means for providing oscillating drive to said vertically
and horizontally movable beams so as to allow an article to be advanced on said horizontally
movable beams while they are above the other set of beams and supported by said other
set of beams during retreating of said horizontally movable beams, said beams being
cantilevered in the direction of article advance and spaced apart at their respective
termini so as to permit insertion of a container both between and beneath said beams
at the termini thereof.
[0006] Another aspect of the invention provides a process for conveying articles in a direction
of progression, characterised by placing an article upon parallel beams extending
in said direction of progression, moving a first set of said beams horizontally along
said direction of progression while the article is supported thereon; effecting vertical
relative movement between said first set of beams and a second set of beams or leave
the article supported on said second set of beams; moving said first set of beams
in a retreating direction opposite said direction of progression while said second
set of beams holds said article above said level; effecting relative vertical movement
in the opposite sense between said first and second sets of beams to support the article
once more on said first set of beams; and moving said first set of beams once more
in the direction of progression while said article is supported thereon.
[0007] In order that the present invention may more readily be understood the following
description is given, merely by way of example, with reference to the accompanying
drawings, in which:-
Figure 1 is a perspective view of one form of apparatus in accordance with this invention;
Figure 2 is a graph illustrating the movement and synchronisation of the horizontally
and vertically movable beams of the apparatus of Figure 1;
Figures 3 and 4 depict one form of motion-producing means for the apparatus shown
in Figure 1; and
Figure 5 illustrates an alternative embodiment of the apparatus of this invention,
showing schematically the motion-producing means thereof.
[0008] It has been found that an apparatus having, in combination, a plurality of cantilevered
beams divided into two sets of which one set is movable in a horizontal mode and another
set is movable in a vertical mode, provides a conveying function to a packaging station
such that meat articles of varying sizes may be packaged at the end of a cantilevered
conveyor without the inconveniences associated with conveyors utilising conventional
conveyor beltso
[0009] Figure 1 depicts in perspective form a cantilevered walking beam bag loader in accordance
with this invention. The apparatus 1 operates in normal walking beam fashion with
two sets of beams each set being operable in a different dimensional mode. The apparatus
comprises a base portion 3 supporting the movable beam assembly on the upper portion
thereof. The beams are of two types, beams 5, 7, 9 and 11 being operable in the horizontal
mode while beams 13. 15 and 17 are operable in the vertical mode. The horizontally
movable beams reciprocate in a horizontal plane while the vertically movable beams
reciprocate in a vertical plane. The relative coordination of the two movements is
such as to produce a forward motion of an article resting on the upper surfaces of
the beam assembly.
[0010] Figure 2 depicts, in the form of a graph, the desired synchronisation of the two
movements.
[0011] The solid line represents the movement of the horizontal beams. Thus when the gradient
of the solid line curve is upward, i.e. positive, the horizontal bars are moved forward,
and when the gradient is negative the horizontal bars are moving in the reverse direction.
[0012] The broken line illustrates the movement of the vertically movable beams such that
when the gradient of the broken line is upward the vertical beams are moving toward
their elevated position. Conversely when the gradient of the broken line is negative
the vertical beams are moving toward their depressed position. The abscissa, which
represents time in arbitrary units, at the zero position represents the attainment
of the level of the horizontally movable beams by the vertically movable beams, and
also the midway travel point for the horizontally reciprocable beams, i.e., a point
halfway between the forward and reverse extent of reciprocal movement.
[0013] Thus, as the horizontally movable beam moves forward to the extent of its forward
position, the vertically movable beams are below the level of the horizontally movable
beams.
[0014] At the end of the forward extent of horizontal movement, the vertically movable beams
rise through the level of the horizontally movable beams to lift a conveyed article
above such level while the horizontally movable beams reciprocate towards the reverse
position. As the horizontally movable beams reach the end of the reverse extent to
move forward again, the vertically movable beams move towards their depressed position
beneath the plane of the horizontally movable beams, such that an article on the conveyor
will rest on the horizontally movable beams during the forward motion thereof.
[0015] Such movement continues in a cyclic fashion to convey an article resting on the surface
of the beams in a forward direction, i.e.. a direction of desired article progression.
[0016] The rate of article progression can be readily controlled by controlling the amplitude
and frequency of the horizontally movable beams. For example, an amplitude of eight
inches at 96 oscillations per minute would give a forward speed of travel of 64 feet
per minute for a conveyed article. It is desirable to have a large amplitude so as
to reduce the number of starts per unit of conveyed distance.
[0017] While many mechanical arrangements may be utilised to bring about the motion described
above for the walking beam loader, a preferred construction is illustrated in Figures
1, 3 and 4 wherein a single power generating means is utilised to provide both the
horizontal and vertical motion.
[0018] Figures 3 and 4 provide a detailed illustration of the operation. For purposes of
simplicity only two horizontally movable beams 19 and 21, and one vertically movable
beam 23, are shown in Figure 3 of the drawings. As is readily apparent from this Figure,
the vertically movable beam operates from a rotatable cylinder cam 25 which provides
the vertical movement required of the beam 23. Cam 25 is operable by power source
such as the motor 27 shown in Figure 4 of the drawings. Cam follower roller 29 carried
at the bottom of vertical shaft 31 is operable for reciprocating the beam 23 in a
vertical plane upon rotation of cam 25.
[0019] Also associated with rotatable cam 25, and carried eccentrically with respect thereto,
is a vertical beam 33 which is mounted eccentrically of the cam 25 and rides within
a longitudinal slot 35 (not shown in Figure 3) of a support beam 37 attached to horizontally
reciprocable beams 19 and 21. Upon rotation of cam 25, the vertical beam 33 riding
within the slot 35 imparts a horizontal reciprocating movement to horizontally movable
beams 19 and 21. It is to be understood that various associated support and stabilising
devices may be incorporated into this structure, for example to ensure that beam 33
remains vertical during its orbiting movement about a vertical axis. One such device
for stabilising the vertically movable beams is illustrated in Figure 4. The rear
portion of vertically movable beam 23 has a stabilising rod 39 which rides within
cylinder 41 for purposes of stabilising the motion of the vertically reciprocable
beam 23. In a like manner the horizontally movable beams are stabilised by mounting
the support beam 37 slidably on tracks 43 and 45 as illustrated in Figure 1 of the
drawings.
[0020] It is readily apparent, however, that various other mechanical devices well within
the skill of the expert in the art could be utilised to provide the requisite motion.
For example, the vertically movable beams may be operated totally independently of
the horizontally movable beams by separate mechanical means.
[0021] In operation it is preferred that the elevation of the vertically movable beam above
the plane of the horizontally movable beams be no greater than one inch at any time.
It has been found that the greater the maximum elevation the greater the tendency
is for conveyed objects to bounce along the conveyor path. For this reason the amount
of elevation should be minimal. It is additionally preferred that the underside of
the vertically movable beams should not rise above the plane of the upper surface
of the horizontally movable beams, as a safety feature to circumvent the possibility
of an operator's finger being trapped beneath the vertically movable beams.
[0022] An additionally preferred feature of this invention is that where scores or tracks
are provided along the surface of the beams these scores or tracks are confined to
the horizontally reciprocable beams. These tracks are illustrated in Figure 3 as scores
44 and 46. The use of such scores or tracks prevents a conveyed object such as a piece
of fresh red meat from sliding on the beams during the conveying process. An unexpected
advantage of utilising scores only on the horizontally reciprocable beams is that
in the event of a power failure, the vertically reciprocable beams may be moved to
their elevated position and utilised as a sliding surface. This is a significant improvement
over the prior art which, during a breakdown or power failure, required manual movement
of meat articles without contacting the otherwise non-sliding surfaces of conveying
belts.
[0023] An additionally preferred feature of the apparatus of this invention is the use of
article- responsive control means for deactivating and activating the operation of
power source 27. For this purpose a depressible trigger 47 is illustrated in Figure
1 of the drawings which deactivates power source 27 upon arrival of a conveyed article
thereon. The deactivation of the drive to the beams permits an operator to drape an
appropriately sized flexible bag through and under the appropriate number of beams
for receipt of the conveyed article. Preferably a knee actuated lever, such as is
shown at 49, permits the operator to reactivate the motor 27 when the bag is properly
positioned for receipt of the conveyed article.
[0024] An alternative embodiment of this invention is shown in Figure 5 where beams 51 and
53 are adapted to operate in a swinging fashion such that each of the beams has both
a horizontal and a vertical displacement during operation. Many mechanical arrangements
are available for this type of construction. However, the arrangement shown in Figure
5 is a simple rotational arrangement wherein reciprocating beams 51 and 53 are attached
by vertical supports 55 to rotating cranks 57. In this arrangement alternate beams
are attached to their respective rotating cranks in a manner so as to be 180° out
of phase with the immediately adjacent beams. This arrangement also provides for a
cantilevered construction to facilitate the loading of a container. This arrangement
may also be facilitated by arranging that one of the sets of beams has a lesser extent
in the direction of progression than the 180
0 offset counterpart.
[0025] This alternative embodiment does not require the use of scores to prevent sliding
since the motion of the conveyed article is continuous. This construction provides
for a smooth sliding surface, in the event of breakdown, regardless of beam position.
[0026] An additional embodiment within the scope of this invention is a modification of
the last discussed embodiment wherein one set of beams is stationary and the other
moves with the composite swinging movement discussed above. In this embodiment the
swinging set of beams, say 51, moves forward while above the plane of the stationary
beams and backward while below the plane of the stationary beams. This embodiment
can be easily visualised from Figure 5 by considering alternate beams to be immobilised.
[0027] While all embodiments discussed above illustrate and describe an arrangement wherein
alternate beams operate in a mode different from the next adjacent beams, it is readily
understood that, if desirable, two or more adjacent beams of the apparatus may be
operable in the similar mode, so long as the net effect is to provide a conveying
action in the desired direction of article progression.
[0028] It is thus seen that the method and apparatus of this invention provide a novel technique
whereby articles may be conveyed into containers. The method and apparatus of this
invention further provide an apparatus which does such conveying without the use of
conventional belts and which provides a sliding surface in the event of a power failure
while at the same time providing an adequate gripping surface when in operation.
1. Apparatus for conveying articles in a direction of progression, characterised by
two sets of beams (5, 7, 9, 11) (13, 15, 17) or (51)(53),at least one (5, 7, 9, 11)
or (51) (53) of said sets being horizontally movable relative to the other set (13,
15, 17) or (53) (51), and at least one (13, 15, 17) or (51) (53) of said sets being
vertically movable so as to be positioned alternately above and below the remaining
set (5, 7, 9, 11) or (53) (51); and means (25, 27, 29, 31, 33, 35, 37) or (55, 57)
for providing oscillating drive to said vertically and horizontally movable beams
so as to allow an article to be advanced on said horizontally movable beams while
they are above the other set of beams and supported by said other set of beams during
retreating of said horizontally movable beams, said beams (5, 7, 9, 11, 13, 15, 17)
or (51,53) being cantilevered in the direction of article advance and spaced apart
at their respective termini so as to permit insertion of a container both between
and beneath said beams at the termini thereof.
2. Apparatus according to claim 1, characterised in that said horizontally movable
beams comprise an upper surface having scores (44, 46) therein to provide a high friction
surface thereon.
3. Apparatus according to claim 1 or 2, characterised in that said set (51,53) of
vertically movable beams is also horizontally movable to provide conveying movement.
4. Apparatus according to claim 3, characterised in that in both sets of beams (51,
53) are both horizontally and vertically movable with one set out of phase from the
other to provide swinging action conveying movement.
5. Apparatus according to claim 3, characterised in that one said set (51) of beams
is both horizontally and vertically movable and the other set is stationary.
6. Apparatus according to claim 3, 4 or 5, characterised in that said means (55, 57)
for providing oscillating drive provides a circular movement to said horizontally
and vertically movable beams (51, 53) whereby said movable beams move in said direction
of article progression when above the plane of the other said set of beams and in
a direction opposite said direction of article progression when below said plane.
7. Apparatus according to claim 6, characterised in that said means for providing
circular movement comprises a rotatable crank (57) and each said movable beam is connected
to said circular movement providing means through a rod (55) rigidly attached to said
movable beam.
8. Apparatus according to claim 1 or 2 characterised in that said vertically movable
beams (13, 15, 17) are vertically reciprocable and said horizontally movable beams
(5, 7, 9, 11) are horizontally reciprocable, whereby said horizontally reciprocable
beams move in an article advancing direction while the vertically reciprocable beams
are below them and in a retreating direction while the vertically reciprocable beams
are above them.
9. Apparatus according to claim 8, characterised in that said means for providing
oscillating drive is a rotatable cam (25) for vertically reciprocating said vertically
movable beams, said cam having attached thereto means (33) for horizontally reciprocating
said horizontally movable beams.
10. Apparatus according to any one of the preceding claims, further characterised
by means (47) for detecting the presence of an article on the conveying surface and
for deactivating said means (25, 27, 29, 31, 33, 35, 37) for providing oscillating
beam movement in response thereto.
11. Apparatus according to claim 10, further characterised by means (49) for reactivating
said means for providing reciprocating movement after deactivation by said detecting
means.
12. A process for conveying articles in a direction of progression, characterised
by placing an article upon parallel beams extending in said direction of progression,
moving a first set (5, 7, 9, 11) or (51) of said beams horizontally along said direction
of progression while the article is supported thereon; effecting vertical relative
movement between said first set of beams and a second set (13, 15, 17) or (53) of
beams to leave the article supported on said second set (13, 15, 17) or (53) of beams;
moving said first set (5, 7, 9, 11) or (51) of beams in a retreating direction opposite
said direction of progression while said second set (13, 15, 17, 19) or (53) of beams
holds said article above said level; effecting relative vertical movement in the opposite
sense between said first and second sets of beams to support the article once more
on said first set of beams; and moving said first set of beams once more in the direction
of progression while said article is supported thereon.
13. A process according to claim 12, characterised in that said second set (13, 15,
17) or (53) is vertically movable and said step of effecting relative vertical motion
between the first and second sets of beams includes moving said second set (13, 15,
17) or (53) vertically; and in that a swinging motion is provided which is synchronised
to convey an article resting on said two sets of beams in said direction of progression.
14. A process according to claim 12, characterised in that said first set (51) of
said beams is moved cyclically with both a horizontal and vertical component, and
said second set of said beams is held substantially stationary; said step of effecting
relative vertical movement between said first and second sets of beams (51, 53) including
lowering said first set (51) of beams towards said second set (53).
15. A process according to claim 14, characterised in that said step of effecting
relative motion between said first and second sets of beams includes raising said
second set (53) of beams towards said first set (51) of beams.
16. A process according to claim 12, 13, 14 or 15, characterised in that said beams
are cantilevered in said direction of article progression and spaced apart from one
another, and in that a flexible container is partially inserted between and under
some of said beams to receive said article being conveyed by said beams.
17. A process according to claim 16 or 17, further characterised by the step of deactivating
the motion of said beams prior to inserting said container and reactivating said motion
when said container is in position.